Elkins, the second teenager accused in the killing, also did not enter a plea when he appeared in court Monday.

Police say De'Marquise Elkins, 17, will be treated as an adult in criminal proceedings.

He was dressed in regular clothes, but his hands and feet were handcuffed and he wore a belt shackle. Elkins' attorney, Jonathan Lockwood, spoke for him during the appearance.

When he arrived in the courtroom, the teen turned to his mother, Karimah Elkins, and nodded.

At the end of the appearance, she said, "I love you, Marquise."

"I'll never hear his first word'

The slain infant's mother, Sherry West, said she was on her way home from the post office last week, pushing her son in a stroller when two males approached.

One of them yelled at her to give him money. She said she didn't have any.

He then proceeded to pull out a gun and shot at the ground. But because West didn't see any shells, she thought the gun was fake.

"I thought he was just using a toy gun to scare me. And then he shot at my head, and the bullet grazed my ear and the side of my head, and then he shot me in the leg, and I still thought that it was a fake gun," she told CNN's "Piers Morgan Live."

But they were able to track down the two suspects and take them into custody, aided by a description from West and others, as well as a check of school attendance records to determine who was not in class Thursday, the day of the shooting.

West said she has no doubt that authorities have her baby's killer in custody: "It's definitely him."

"I just hope, you know, that the shooter dies. I mean, I had to watch my baby die and I want him to die. A life for a life," she said.

Immediately after the shooting, detectives searched her home for a gun and conducted gun residue tests on both her and the baby's father, West said, adding that the tests were negative and the search did not turn up a gun.

Citing the ongoing investigation, police spokesman Todd Rhodes declined to comment when asked about the search and those tests.

West also said she relinquished a jacket she was wearing at the time of the shooting to a detective. She told police she was grabbed or shoved briefly by the suspected shooter, and they hope to lift a fingerprint off the jacket, she said.

This isn't the first time West has lost a son to violence.

Her 18-year-old son was stabbed to death in 2008 in New Jersey, she said.

"This is the second child that people have taken from me in a tragic way," West said. "I'm so afraid to have any more babies now. I tried to raise really good kids in a wicked world."

911 calls reveal witnesses' horror

Police in the coastal city of Brunswick released to CNN three recordings of 911 calls about Thursday's shooting.

"A baby has been shot!" one woman said in a 911 call.

The exchange with the emergency operator was emotionally charged.

"Listen to me, ma'am! Is the baby breathing?" the operator replied.

"I don't know," the woman said.

She began to cry.

"Listen to me!" the operator said to the weeping woman. "We have people en route. Did you hear shots in the area?"

Yes, she heard shots, she said.

"Be calm," the operator said. "How many shots did you hear?"

"I heard like three shots. And the baby has been shot in the head," the woman said.

The woman was so distraught that she passed her cell phone to a man walking his dog.

"No, the baby is not breathing," the man told the operator.

"The baby was shot in the head?" the operator continued.

"Yes, right between the eyes," the man said, adding that he earlier heard a "small-caliber clap."

As he spoke, sirens wailed as police arrived on the scene, and the man broke off the phone call.